Pneumatic door closer device



Nov. 24, 1959 B. A. QUINN PNEUMATIC DOOR CLOSER DEVICE Filed Nov. 19.1956 I N VEN TOR.

Arme/V56 Ullid, Staf-CS Patent O "ice,

p a fz91s,7`57 l .f i PNMAIOOR CLOSER DEVICE l 'iir't Alquimi; sf. Paul,Minn. V Appiictiun November 19, 1956, serial No. 623,206 '(cl. 16-66) iMyinvention relates to improvements in pneumatic door closing devicesand is in the nature of a modification of the structure dislosedandbroadly claimed inmy copending application, Pneumatic Door CloserDevice, S. N. 623,109, filed of even date herewith.

As pointed out in my copending application above identified, whenconventional spring actuated pneumatic piston and cylinder door closingdevices are used in connection with light weight doors such as aluminumdoor's, the swing of the door is Vso rapid that bouncing or reboundinginvariably resultsduring the iinal closing movements of the door due torapid compression of the air within the cylinder. a

The primary object of my invention is the provision of a device of theclass above described which is provided not only with means for limitingthe bouncing or rebounding action of the door during its linal closingmovements vbut which. is also provided with meansf for partiallyoffsetting the force progressively exerted by the coil compressionspring within the cylinder, during iinal opening movements of the door.

A further object of my invention is the provision of means, whereby thedecreasing yielding bias of the coil spring during final door closingmovements, is supplemented. r

A still further object of my invention is the provision of means wherebythe increasingly greater yielding bias exerted upon the door by the coilcompression spring during opening movements thereof, is partially offsetduring final door opening movements.

A still further object of my invention is the provision of a novelarrangement of parts whereby yielding means interposed between the doorand the door closing piston cylinder (and working at substantially rightangles to the coil spring within the piston) creates constant butvariable friction between the connecting rod and the end of the cylinderin which it is slidably mounted, whereby to eifect steadying movementsto the door throughout its entire range of closing movements.

A further object of my invention is the provision of a device in theform of an attachment for conventional pneumatic cylinder and pistondoor closing devices which will eliminate bouncing or rebounding of thedoor during final closing movements thereof, and which will alsopartially offset the force of the coil compression spring within thecylinder during' nal opening movements of the door.

A further object of my invention is the provision of a device of theclass immediately above described, which is relatively inexpensive toproduce, which has a minimum of working parts, which is rugged anddurable in construction, and which is foolproof in its operation.

The above and still further objects of my invention will become apparentfrom the following detailed specification, appended claims and attacheddrawing.

Referring to the drawing, wherein like characters of reference indicatelike parts throughout several views:

p 2,913,757 Baier-.fed Nov. 24, '195s 2 Fig. 1 is avview in transversesection of a conventional frame and cooperating hinged door, showing mynovel device in top plan,

Fig. 2 is an enlarged fragmentary sectional view as seen substantiallyfrom the line 2-2 of Fig. 1, and

Fig. 3 is an enlarged sectional view as seen substantially from the line3--3 of Fig. 1.-

Referring with greaterparticularity to the drawing, the numerall,indicates in its entirety a door frame to which a door 2 is hingedlysecured, as at 3.

v The "spring-operated pneumatically-controlled door closer, hereinbroadly referred to as an extensible and retractable device includes anelongated tubular cylinder 4, a connecting rod 5, a piston or plunger 6mounted fast on the inner end of the plunger rod 5 within the cylinder4and a coil compression spring 7 which is compressed between the piston6 and the innerend 8 of the cylinder ,4. It will be noted that theplunger rod 5 projects through and is slidably mounted for extending andretracting movements in end 8 of the cylinder 4.

The construction of the' cylinder 4, the piston 6 and immediatelyassociated parts, including suitable means for ,controlling the escapeof air from the end 9 of the cylinder 4 during retracting movements ofthe connecting rod 5, form no`part of the instant invention and hencewill` not be explained in detail. It sulces to state that a 'Patent2,646,589 dated July 28, 1953.

suitablev arrangement of such parts is disclosed in my As shown, theprojectedend of the connecting rod 5 1s pivotally secured to a suitablebracket 10, as. indicated at 1-1. Bracket 10 in turn is secured to thedoor framev 1 in laterally `inwardly spaced relationship't thedoor.2,with the axis of the pivotal connection 11 in parallel relationship tothe axis of swinging movement of the hinge means 3. The outer end 9 ofthe cylinder 4 is pivotally secured as at 12 to a suitable bracket 13detachably securable to the door 2 by any suitable means such as screws14. The axis of pivotal connection 12 is parallel to the axis of pivotalconnection 11.

A coil tension spring 15 is shown as encompassing the cylinder 4,intermediate the ends 8 and 9 thereof and preferably in relativelyclosely spaced relationship to .the inner end 8. The hooked oppositeends 16 of the coil spring 15 pass through apertured ears 17 carried bya mounting plate 18 preferably adapted to be detachably secured to thedoor 2. As shown particularly in Fig. 3, the unnumberedcircumferentia'lly extended axially spaced flanges form a nest for thecoil spring 15 and positively preclude axial movements of the spring 15with respect to the cylinder 4.

By this novel arrangement above described, one effectively has a primaryspring means, namely the coil compression spring 7 which exerts ayielding bias on the cylinder 4 and cooperating connecting rod equippedpiston 6 generally longitudinally thereof to impart retracting- (doorclosing) movements thereto, and a secondary spring means, namely thecoil tension spring 15, which exerts a yielding bias on the cylinder 4and connecting rod equipped piston 6 carried thereby at right angles tothe longitudinal dimensions thereof in the direction of the door 2. Upto a given point, the primary spring 7 and the secondary spring 15 bothexert an independent yielding bias upon the door 2 to move same towardthe closed full line position of Fig. l upon the hinges 3, the coilspring 7 exerting a progressively greater bias as-the door 2 approachesits maximum opened position.

This point is reached at dead center with respect to connections 3, 11and 12. Beyond this dead center position, the action of the coil tensionspring 15 is reversed and consequently, through connections 3, 11 and12, said spring 15 exerts a yielding bias on the door 2 in a directionopposite to that exerted by the coil spring 7, namely i in a directionto impart opening movements to theqdoor 2. This yielding bias offsets toa degree the progressively increasing bias of the coil spring 7 toimpart closing movements to the door 2. Thus, when the door 2 isreleased at this point, its initial closing movements are notgob`jectionably rigid and violent (as is customary in devices 'of thischaracter) but rather are slow and gentle.

Furthermore, if the door 2 approaches the full line closed position ofFig. 1, the bias exerted by the coil spring 7 becomes progressivelyless. At'this point, the coil tension spring 15 acts as a booster tototally overcome the rebounding or bouncing action of the door 2, abovedescribed.

Another feature of importance is as follows: The coil tension spring 15,working at substantially right angles to the conventional coilcompression spring 7 within the cylinder 4, creates constant butvariable friction between the connecting rod and the end 8 of thecylinder 4 in which it is slidably mounted. This is clearly illustratedin Fig. l of the drawing. As shown by the intermediate relatively longbroken line showing, the friction between the connecting rod 5 and theend 8 of the cylinder 4 is greatest at this intermediate position of thedoor 2 because of the greater angularity between the cylinder 4 and thedoor 2. This angularity becomes less as the door 2 approaches either theextreme open (illustrated by relatively small broken lines) position orthe closed posi'- tion shown by full lines. This frictional engagementimparts steadying movements to the door 2 during its entire closingmovements, and is also a factor in the eliminating of the bouncing orrebounding action of the door 2 as it approaches its closed position.

My invention has been thoroughly tested and found to be completelysatisfactory for the accomplishment of the above objects and while Ihave disclosed a preferred embodiment thereof, it should be specificallyunderstood that same is capable of considerable modification withoutdeparture from the scope and spirit of the appended claims.

What I claim is:

l. A pneumatic door closer comprising a cylinder element and apiston-equipped plunger element mounted for extending and retractingmovements relative to said cylinder element, meansy for pivotallyconnecting one end of one of said elements to adoory frame oiy an axisparallel to the axis of swinging movements of a cooperating door in saidframe, means' for pivotally connecting the opposite end'of the other ofsaid elements to said door on an axis parallel to said first-mentionedaxis, means within saidV cylinder element yieldingly biasing saidplunger element in a retracting direction relative to said cylinderelement, and independent yielding means carried by one of said elementsintermediate said pivotal connections, said independent yielding meansexerting a yielding bias 'at substantially right angles to the directionof the bias of said first-mentioned yielding means in the direction ofsaid door, said independent yielding means comprising a tension springconnected to an intermediate portion of said cylinder and having atleast one end thereof connected to the door.

2. The structure defined in claim 1 in which said tension spring is acoil spring encompassing said cylinder, and in further combination withmeans on said cylinder anchoring said coil spring against movementlongitudinally thereof.

Perregrine .Tune 1l, 1901 Bowles Feb. 28, 1922

